Rewterz Threat Advisory – Multiple Vulnerabilities in Mozilla Firefox

Severity

High

Analysis Summary

CVE-2018-6156

Incorrect derivation of a packet length in WebRTC caused heap corruption via a crafted video file. This resulted in a potentially exploitable crash.

CVE-2019-15903

In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early. A subsequent call to XML_GetCurrentLineNumber or XML_GetCurrentColumnNumber then resulted in a heap-based buffer over-read.

CVE-2019-11757

When storing a value in IndexedDB, the value’s prototype chain is followed and it was possible to retain a reference to a locale, delete it, and subsequently reference it. This resulted in a use-after-free and a potentially exploitable crash.

CVE-2019-11760

A fixed-size stack buffer could overflow in nrappkit when doing WebRTC signaling. This resulted in a potentially exploitable crash in some instances.

CVE-2019-11761

By using a form with a data URI it was possible to gain access to the privileged JSONView object that had been cloned into content. Impact from exposing this object appears to be minimal, however it was a bypass of existing defense in depth mechanisms.

CVE-2019-11762

If two same-origin documents set document.domain differently to become cross-origin, it was possible for them to call arbitrary DOM methods/getters/setters on the now-cross-origin window.

CVE-2019-11763

Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly parsing these entities. This could have led to HTML comment text being treated as HTML which could have led to XSS in a web application under certain conditions. It could have also led to HTML entities being masked from filters, enabling the use of entities to mask the actual characters of interest from filters.

CVE-2019-11765

A compromised content process could send a message to the parent process that would cause the ‘Click to Play’ permission prompt to be shown. However, due to lack of validation from the parent process, if the user accepted the permission request an attacker-controlled permission would be granted rather than the ‘Click to Play’ permission.

CVE-2019-17000

An object tag with a data URI did not correctly inherit the document’s Content Security Policy. This allowed a CSP bypass in a cross-origin frame if the document’s policy explicitly allowed data: URIs.

CVE-2019-17001

A Content-Security-Policy that blocks in-line scripts could be bypassed using an object tag to execute JavaScript in the protected document (cross-site scripting). This is a separate bypass from CVE-2019-17000.
Note: This flaw only affected Firefox 69 and was not present in earlier versions.

CVE-2019-17002

If upgrade-insecure-requests was specified in the Content Security Policy, and a link was dragged and dropped from that page, the link was not upgraded to https.

CVE-2019-11764

Mozilla developers and community members Bob Clary, Jason Kratzer, Aaron Klotz, Iain Ireland, Tyson Smith, Christian Holler, Steve Fink, Honza Bambas, Byron Campen, and Cristian Brindusan reported memory safety bugs present in Firefox 69 and Firefox ESR 68.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could be exploited to run arbitrary code.

Impact

• Heap based buffer over-read
• Use after free
• Execution of arbitrary code
• Security bypass
• Incorrect permissions

Affected Vendors

Mozilla

Affected Products

Firefox

Remediation

Update to Firefox 70.0.